None of the research conducted to date has been able to discover a single life form that represents the supposed evolutionary forebear of the mantis shrimp. No findings indicate that mantis shrimp came into being through any process of evolution. Every fossil unearthed shows that mantis shrimp have always existed as mantis shrimp and have remained unchanged for millions of years.
One such fossil is the 95-million-year-old mantis shrimp specimen pictured here.